Alexander Grigorievich Stoletov

1.

Aleksandr
Stoletov

2.

Alexander Grigorievich
Stoletov was
a Russian physicist, founder
of electrical engineering, and
professor in Moscow
University.
He was born on the 10th of
August, 1839 in Vladimir.

3.

He studied at the Vladimir gymnasium. After
graduating from high school with honors, he entered
the physics and mathematics Department of the
Imperial Moscow University and also graduated with
honors.
He took an internship abroad, studying physics in
Heidelberg, Gottingen, Berlin and Paris.

4.

In February 1866 he began
lecturing on mathematical
physics and physical
geography at the Imperial
Moscow University.
Stoletov was considered a
strict teacher. He was
known for asking all sorts
of tricky questions, then
looked blankly at the
student with a stony face
and mercilessly failed one
by one.

5.

Contribution to science
• His major contributions include pioneer work in the
field of ferromagnetism and discovery of the laws and
principles of the outer photoelectric effect.

6.

Magnetism
• Stoletov was the first to show that with the increase
of the magnetic field the magnetic susceptibility of
iron grows, but then begins to decrease.
• He built the curve of the magnetic permeability of
ferromagnetics, known as the Stoletov curve.
• Also he eveloped two new methods for measuring
magnetic properties of various materials.

7.

Photoelectric effect
• Studied the outer photoelectric effect, discovered by Hertz in
1887. Published the results in six works.
• Developed quantitative methods for the study of the
photoelectric effect.
• Discovered the direct proportionality between the intensity of
light and the corresponding photo induced current (Stoletov's
law)
• Discovered the Stoletov constant which defines the ratio
between the intensity of the electric current and the gas
pressure under the maximum current.
• Built the first solar cell based on the outer photoelectric effect
and estimated the response time of the photoelectric current.
• Discovered the decrease of the solar cell's sensitivity with time
(fatigue of solar cells).

8.

• Also he calculated the proportion between
electrodynamic and electrostatic units, producing a
value very close to the speed of light.

9.

• Today there is a monument
to Stoletov in front of the
building of physics
department of the MSU on
Vorobyovy Gory.
• Since 2009, Vladimir state
University has been named
after Stoletov.
• The Russian Academy of
Sciences awards the A. G.
Stoletov Prize for
outstanding work in
physics.